High-Tech CU-Boulder Plant Chamber To Fly On Upcoming Shuttle Mission

March 31, 1997

A high-tech plant-growth chamber developed at the University of Colorado at Boulder that contains intriguing pharmaceutical and agricultural experiments will blast off on NASAs space shuttle Columbia from Florida April 3.

The payload and experiments were developed by faculty, students and industry affiliates from the BioServe Space Technologies Center -- headquartered in CUs aerospace engineering sciences department -- in collaboration with a team at the NASA-Ames Researcher Center in Moffett Field, Calif. Researchers are using the low-gravity space environment to develop products and technologies in life science, agriculture and medicine, said BioServe Associate Director Louis Stodieck.

Two BioServe experiments sponsored by a large U.S. pharmaceutical company are testing the effects of microgravity on plant species known as sweet wormwood and rosy periwinkle. Both plants naturally produce tiny quantities of pharmaceutically inportant compounds --one plant makes an anti-malarial drug while the other produces precursors to anticancer agents, he said.

Previous Bioserve experiments indicate that significantly less lignin -- a substance in plants that affects their strength and stiffness -- is produced in microgravity. We are hypothesizing that a decrease in lignin production in space may lead to an enhancement in other plant metabolic pathways which are of commercial benefit, said Gerard Heyenga, a principal science investigator on the study from NASA-Ames. Increased production of plant secondary compounds could ultimately lower the costs of certain pharmaceuticals or lead to the development of new drugs.

Seven experiments will be aboard the second shuttle flight of BioServes Plant Generic Bioprocessing Apparatus, or PGBA, which first flew in May 1996. The 125-pound, automated plant-growth facility will be used to grow food and pharmaceutical and forest plants in space, said BioServes Alex Hoehn, who headed up the design and development of the television-sized plant chamber.

We are entering a new era in space as plans for the construction of the international space station move ahead, said Stodieck. Because much of the cargo space aboard shuttles will be used to ferry building materials into orbit in the coming years, there will be fewer flight opportunities for scientific experiments like those from BioServe, which has flown experiments on 12 shuttle missions.

But once the space station is assembled we expect to have near continuous access to space over the long duration needed to complete many of these experiments, said Stodieck. While the upcoming Columbia mission will provide nearly 16 days of microgravity, the space station will be able to provide months or even years that may be required for particular commercial investigations, especially those involving plants.

The PGBA will occupy the Express Rack aboard Columbia. Designed by Marshall Space Flight Center, the novel rack will eventually permit experiments to be quickly transferred from NASA shuttles to the International Space Station. Three of the seven astronauts on Columbia have been trained to use the BioServe plant chamber and will help manipulate experiments during the mission.

The PGBA is by far the largest plant growth chamber to be flown on a shuttle that can precisely control carbon dioxide, temperature, humidity and light conditions, said Stodieck. It also is the first plant-growth system with direct data uplink, downlink and video capabilities, allowing BioServe faculty and students to control and manipulate experiments from the CU-Boulder campus, he said.

In cooperation with Dean Foods Vegetable Co. of Green Bay, Wisc., BioServe also will fly spinach plants in the chamber. A better understanding of the effects of low gravity on the structure, tenderness and production of sugars, starch and fatty acids in spinach may help researchers develop more tender varieties for dinner tables and heartier strains of vegetables that can withstand severe weather.

BioServe also will fly loblolly pine seedlings for Georgia Pacific of Atlanta to monitor lignin and wood formation. Such low-gravity research efforts could benefit the forest products industry by allowing for the eventual development of superior strains of commercial lumber and paper products, said Heyenga.

Researchers and students from Kansas State University, a joint partner in BioServe, will fly additional experiments in the PGBA. One will test the effects of microgravity on tomato gene expression, while the second will investigate methods of infecting cereal crops with nitrogen-fixing bacteria known as rhizobia that naturally benefit legumes like peas and beans by snaring nitrogen from the atmosphere.

Developing ways of infecting crops like corn and wheat with rhizobium could help reduce the need for fertilizers on Earth, researchers believe.

BioServe is a joint center of CU, KSU and industrial affiliates and one of 11 NASA Centers for Space Commercialization with active space flight programs.